Port member of superconducting accelerating cavity

Abstract

Provided is a port member of a superconducting accelerating cavity, the entire size of which is reduced and which has enhanced working efficiency to achieve a lower manufacturing cost. In a pickup port ( 23 ) of a superconducting accelerating cavity, one end is joined by welding to a port portion ( 27 ) formed on a higher order mode coupler ( 13 ) which is provided at an end of a cavity body, while the other end is joined by flange coupling to a pickup antenna ( 22 ). A port body ( 33 ) and a flange portion ( 35 ) are integrally formed of a niobium material having low purity or a niobium alloy containing a component other than niobium at a percentage lower than a prescribed percentage. The flange coupling is achieved with use of a quick coupling ( 41 ).

The invention claimed is: 
     
       1. A port member of a superconducting accelerating cavity comprising:
 a port body welded to a port portion formed in a beam pipe part provided at an end of a cavity body, the beam pipe being formed of a niobium material having high purity; and 
 a first flange portion configured to be attached to an external structure, 
 wherein both the port body and the first flange portion are integrally formed of a niobium material having lower purity than that of the beam pipe part or a niobium alloy containing a component other than niobium at a percentage lower than a prescribed percentage, 
 wherein the first flange portion is attached to a second flange portion included in the external structure by a quick coupling, 
 wherein the first flange portion and the second flange portion are tightened by the quick coupling in the state where a sealing member is interposed therebetween, 
 wherein the quick coupling includes a plurality of fitting portions which are connected with each other so that a peripheral length of the quick coupling can be changed and a clamp member which reduces the peripheral length of the quick coupling, and 
 wherein the fitting portion is configured to apply a predetermined planar pressure to the sealing member when a predetermined peripheral length is obtained. 
 
     
     
       2. The port member of the superconducting accelerating cavity according to  claim 1 , wherein
 as the niobium alloy, a niobium zirconium alloy having a zirconium content of 1 to 10weight % is used. 
 
     
     
       3. The port member of the superconducting accelerating cavity according to  claim 1 , wherein
 as the niobium alloy, a niobium hafnium alloy having a hafnium content of 1 to 10weight % is used.